Full Cover Roofing : Insulation

Radiant Barriers
Radiant barriers are installed in homes—most commonly in attics—to reduce summer heat gain and winter heat loss, which helps lower heating and cooling costs. The barriers consist of a highly reflective material that reflects radiant heat rather than absorbing it. They don't, however, reduce heat conduction like thermal insulation materials.

Research conducted by  the FLORIDA SOLAR ENERGY CENTER (FSEC) the installation of a radiant barrier can generate significant financial saving. The summer peak energy use savings was as much as 27%. This study also showed that the average peak reduction from the radiant barrier system was three times as great as the savings produced by adding more fiberglass insulation.

How They Work
Heat travels from a warm area to a cool area by a combination of conduction, convection, and radiation. Heat flowsInsulation_diagram by conduction from a hotter location within a material or assembly to a colder location. Heat transfer by convection occurs when a liquid or gas is heated by a surface, becomes less dense, and rises (natural convection), or when a moving stream of air absorbs heat from a warmer surface (forced convection). Radiant heat travels in a straight line away from any surface and heats anything solid that absorbs the incident energy. Radiant heat transfer occurs because warmer surfaces emit more radiation than cooler surfaces.
When the sun heats a roof, it's primarily the sun's radiant energy that makes the roof hot. A large portion of this heat travels by conduction through the roofing materials to the attic side of the roof. The hot roof material then radiates its gained heat energy onto the cooler attic surfaces, including the air ducts and the attic floor. A radiant barrier reduces the radiant heat transfer from the underside of the roof to the other surfaces in the attic.

A radiant barrier's performance is determined by three factors:

  • Emissivity (or emittance) – the ratio of the radiant energy (heat) leaving (being emitted by) a surface to that of a black body at the same temperature and with the same area. It's expressed as a number a between 0 and 1. The higher the number, the greater the emitted radiation.

  • Reflectivity (or reflectance) – a measure of how much radiant heat is reflected by a material. It's also expressed as a number between 0 and 1 (sometimes, it is given as a percentage between 0 and 100%). The higher the number, the greater the reflectivity.

  • The angle the incident radiation strikes the surface—a right angle (perpendicular) usually works best.

All radiant barriers must have a low emissivity (0.1 or less) and high reflectivity (0.9 or more). From one brand of radiant barrier to another, the reflectivity and emissivity are usually so similar that it makes little difference as far as thermal performance. (Most products have emissivities of 0.03–0.05, which generally corresponds to a reflectivity of 95% – 97%.) Also, the greater the temperature differences between the sides of the radiant barrier material, the greater the benefits a radiant barrier can offer.
Radiant barriers are more effective in hot climates than in cool climates, especially when cooling air ducts are located in the attic. Some studies show that radiant barriers can lower cooling costs between 5%–10% when used in a warm, sunny climate. The reduced heat gain may even allow for a smaller air conditioning system. But in cool climates, it's usually more cost effective to install more than the minimum recommended level of insulation rather than a radiant barrier.

Types of Radiant Barriers
Radiant barriers come in a variety of forms, including reflective foil, reflective metal roof shingles, reflective laminated roof sheathing, and even reflective chips, which can be applied over loose-fill insulation. The reflective material, usually aluminum, is applied to one or both sides of a number of substrate materials. Substrate materials include kraft paper, plastic films, cardboard, oriented strand board, and air infiltration barrier material. Some products are fiber-reinforced to increase the durability and ease of handling.

Also, radiant barriers—which don't provide a significant amount of thermal insulation—can be combined with many types of insulation materials. These combinations are called reflective insulation systems. In these combinations, radiant barriers can also act as the insulation's facing material.

HELPING YOUR ROOF TO BECOME MORE ENERGY EFFICIENT

Full Cover Roofing is committed to contribute to the environment and help to mitigate the impact of global warming and climate change on our planet. The least we can do is to educate and inform our clientele of the potential benefits of becoming more energy efficient. This would not only help reduce carbon dioxide emissions but would also translate into savings for you. Making your house more energy efficient or green embraces several areas of the building that require upgrading or modification. The roof is just one of them. Roofing is what we do and from a roofer standpoint, we can provide some tips.

COLORS MATTER
The chart and graph show superior energy savings at peak demand hours for light colored roofs (obtained from the Florida Solar Energy Center).

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REFLECTIVITY IS IMPORTANT

RADIANT BARRIERS
Using radiant barriers helps you reduce the heat transfer into your attic lowering the temperature inside and thus into your home. As a result, the demand of work for your A/C system decreases providing more energy savings or lower electric bills.
Chart (Obtained from the Florida Solar Energy Center)

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BENEFITS
Florida Energy Code Credit
Utility Rebate

ENERGY SAVING TILE ROOFS
Some of the tile manufacturers that we work with also offer products that would enable us to use a method of installation that would make your roof cooler. It would be our pleasure to inform you and answer any questions that you may have about it.

More Info
better than 70% of our insulation sales. ICC-ES Recognized (4’x175’ roll only) and ENERGY STAR qualified, this 15.67 R-value product - details, reflects 97% of radiant heat (the primary source of heat flow). Ozone friendly and safe to work with, Prodex is used in homes, metal buildings, pole barns, and much more. Metal building owners love the fact that it can eliminate condensation - It keeps their structures cool and dry in summer and warm in winter. Contractors like the fact that it’s easier to install and adds value to their jobs. Unlike fiberglass
insulation, it contains no itchy fibers to breathe or cause skin irritation. No asbestos, or toxic vapors in case of fire in this ultimate energy saving product. Built for consistency in performance, Prodex handles punctures and temperature extremes better than bubble wraps. Unaffected by humidity and water, Prodex doesn’t mildew or promote fungus growth. Two layers of reflective aluminum foil surrounding a 1/4-inch closed-cell Polyethylene foam center. Prodex Total Insulation is the most cost effective reflective insulation.

  • Reduces or eliminates condensation (very important in metal buildings!)

  • Provides Class A/Class 1 fire rated protection

  • Reflects 97% of radiant energy

  • Does not mildew or promote fungus growth

  • Unaffected by humidity and water.

  • Does not provide nesting for birds, rodents or insects

  • Vapor Barrier, waterproof and non-absorbent

  • Can be stapled, nailed, glued or sewn.

  • Clean, Lightweight, Flexible & Very Strong.

  • Is used in animal confinement buildings to reduce the "black globe effect"

  • Convenient flange tabs on sides